Preservation of minimally processed 'aurora-1' peaches using additives

'Aurora-1' peaches establishes an interesting alternative as a minimally processed product, due to its characteristics like flavor, color, smell, and also because of its handling resistance. However, it has a short shelf life after a fresh-cut due to enzymatic browning and stone cavity collapse. The main purpose of this research was to test the additive with antioxidant effect to prevent browning in minimally processed 'Aurora-1' peaches. The minimal processing consists of washing, sanitizing, peelings and fruit stone extraction. After that, longitudinal cuts were made to obtain eight segments per fruit. The slices were immersed into the following treatment solutions: control (immersion in 2% ascorbic acid); 2% ascorbic acid + 2% calcium chloride; 1% sodium isoascorbate; 1% citric acid; 1% L-cysteine hydrochloride. The products were placed into rigid polystyrene trays branded MEIWA M-54, covered with 14 µm PVC film (OmnifilmTM) and kept in cold storage at 3ºC ± 2ºC and 65% RH for twelve days, and evaluated each three days. Appraised variables were appearance, soluble solids, titratable acidity, soluble carbohydrates and reducing sugars, total and soluble pectin, ascorbic acid, and peroxidase and polyphenol oxidase enzyme activity. L-cysteine gave to the minimally processed products a shelf life of twelve days, limmited by off-flavor. The treatment with ascorbic acid was efficient to maintainthe ascorbic acid content, with a shelf-life of nine days, limited by enzymatic browning.

Avaliação do teor e da estabilidade de vitaminas do complexo B e vitamina C em bebidas isotônicas e energéticas

Vitamin C stability and concentration was evaluated in isotonic beverages and B group vitamins (B1, B2, B3, B5 and B6) in power beverages. The amount of vitamins was found to be above of that declared on the labels, even after the shelf life had been exceeded. A small decrease in the amount of B group vitamins was observed during the shelf life of the products. In the case of vitamin C this decrease was slightly higher. The present research shows the need of increased quality control and inspection.

Tempo de vida útil de propelentes base-simples

The purpose of this work was to determine the safe shelf life of single-base propellants. The kinetic parameters relative to the consumption of the stabilizer diphenylamine (DPA) added to the propellant were determined as a function of the storage and ageing time. High Performance Liquid Chromatography (HPLC) with spectrophotometric detection was used to determine the DPA percentage before and after the artificial ageing at 60, 70 and 80 ºC. The experimental data were very well adjusted to a pseudo-first order kinetic model and the respective kinetic constants are 8.0-10-3 day-1 (60 ºC); 1.9-10-2 day-1 (70 ºC); 1.2-10-1 day-1 (80 ºC). The activation energy was calculated as 130 kJ mol-1 and the half-time for depletion of the DPA at the hypothetical temperature of 40 ºC of storage was estimated as being 6 years.

Determination of moisture content and water activity in algae and fish by thermoanalytical techniques

The water content in seafoods is very important since it affects their sensorial quality, microbiological stability, physical characteristics and shelf life. In this study, thermoanalytical techniques were employed to develop a simple and accurate method to determine water content (moisture) by thermogravimetry (TG) and water activity from moisture content values and freezing point depression using differential scanning calorimetry (DSC). The precision of the results suggests that TG is a suitable technique to determine moisture content in biological samples. The average water content values for fish samples of Lutjanus synagris and Ocyurus chrysurus species were 76.4 ± 5.7% and 63.3 ± 3.9%, respectively, while that of Ulva lactuca marine algae species was 76.0 ± 4.4%. The method presented here was also successfully applied to determine water activity in two species of fish and six species of marine algae collected in the Atlantic coastal waters of Bahia, in Brazil. Water activity determined in fish samples ranged from 0.946 - 0.960 and was consistent with values reported in the literature, i.e., 0.9 - 1.0. The water activity values determined in marine algae samples lay within the interval of 0.974 - 0.979.

Quantificação de TBHQ (terc butil hidroquinona) e avaliação da estabilidade oxidativa em óleos de girassol comerciais

Sunflower oil is one of the vegetable oils most susceptible to oxidative reaction. Therefore the presence of natural (tocopherol) and/or synthetic (TBHQ) antioxidants is a prerequisite to secure the stability of this oil during its shelf life, especially with the increased use of PET packaging. On determining the total tocopherol content in 10 samples of deodorized sunflower oils, high losses in total tocopherol during deodorization were identified. In order to facilitate researche involving oxidative stability of vegetable oils, a method for isolated quantification of TBHQ using the isocratic elution system was developed.

Validação de método para a determinação de 5-hidroximetilfurfural em mel por cromatografia líquida e sua influência na qualidade do produto

In honey 5-hydroxymethyl-2-furaldehyde (HMF) is one of the most typical products of degradation: it is usually absent in fresh honey, but its concentration tends to rise as a result of heating processes or long-term storage. The validation protocol was performed in terms of detection and quantification limits, precision (by repeatability and intermediate precision), linearity and accuracy (by recovery tests). The method has been tested on 15 honey samples of different ages and geographical origin. HMF correlated highly with the age of the samples has been considered a very important parameter to put these honeys on the market or not and/or to estimate their shelf life.

Análise térmica aplicada a fármacos e formulações farmacêuticas na indústria farmacêutica

Several matters of the pharmaceutical demonstrate the great importance of thermal analysis application, especially TG and DSC for the pharmaceutical industry future, namely: characterization of the drugs with the thermal events definition, in studies of drug purity, in the polymorphs identification, in compatibility studies of solid dosage pharmaceutical formulations, in drugs and pharmaceutical formulations thermal stability, and in determination of shelf life for isothermal degradation kinetics by extrapolation using the Arrhenius equation. Thus, the test results obtained from thermal analysis are directly related to the quality of a pharmaceutical product, whether the stability or bioavailability of the pharmaceutical product.

Filmes de amidos de mandioca modificados para recobrimento e conservação de uvas

In this article, films were produced with six types of cassava's starch mixed with gelatin and plasticized with sorbitol. These films were used in covering of grapes 'Benitaka' (Vitis vinifera L.) as biodegradable packaging. The acetylated starch film showed the best results in solubility, thickness and homogeneity, besides the less water loss the fruit, resulting in better coverage, increasing the shelf life fruits in 12 days. These results demonstrate the great potential of using films in food conservation, adding value to agricultural activity and helping to reduce non-biodegradable plastics in the environment.

Guia para a determinação da estabilidade de produtos químicos

Companies worldwide are reviewing their working process to avoid waste, become aligned with environmental management standards and to fulfill specifications defined for national and international regulations. In this context, it is important that Brazilian Chemical companies have a specific stability guide for their products. The main purpose of this work is to present a stability guide for chemical products based on the existing guides of the Pharmaceutical and Cosmetics segments. Furthermore, this work proposes to offer an additional period of shelf life for chemical products, provided they meet certain prerequisites.

Nanocompósito de polpa de mamão e nanopartículas de quitosana para aplicação em embalagens

Nanocomposite materials have been incorporated into biopolymers, (e.g. hydroxypropyl methylcellulose), to improve their physical and chemical properties and enable them to be applied in food packaging, especially for their biodegradable and renewable properties. With this addition, fruit puree has been incorporated into the films to confer nutritional properties besides color and flavor. Chitosan is of interest in the packaging field since it is a biodegradable, bioabsorbable, antimicrobial agent. Furthermore, chitosan nanoparticles have been widely explored for their interesting properties and potential applications in food packaging. This work was divided into two stages: (1) chitosan nanoparticle synthesis; (2) addition of nanoparticles into HPMC and papaya puree films. Addition of chitosan nanoparticles to HPMC and papaya puree films improved film properties: mechanical, thermal and water vapor barrier. We have developed a novel nanomaterial with great potential for application in packaging to prolong the shelf life of food.

Effect of temperature, wetness duration and cultivar on the development of anthracnose in guava fruits

The development of a large number of postharvest diseases is closely associated with fruit ripeness. Environmental conditions may affect both the pathogen development and the fruit ripening rate. The aim of this study was to determine the most favorable temperature and wetness duration to the development of anthracnose in guava fruits. Cultivars 'Kumagai' (white pulp) and 'Pedro Sato' (red pulp) were inoculated with a conidial suspension of Colletotrichum gloeosporioides and C. acutatum and incubated at constant temperature ranging from 10 to 35ºC and wetness duration of 6 and 24 hours. Disease severity and incidence were evaluated at every two days during 12 days. No infection occurred at 10 and 35ºC, regardless of the wetness duration. The optimum conditions for fruit infection were 26 and 27ºC for 'Kumagai' and 25 and 26ºC for 'Pedro Sato', adopting 24 hours of wetness. In general, the disease development in 'Kumagai' cultivar was more affected by the wetness period, compared to 'Pedro Sato'. Disease severity for 'Kumagai' fruits was maximal between 25 and 30ºC , depending on the Colletotrichum species. Regarding 'Pedro Sato', the mean diameter of lesions was greater in fruits stored at 20, 25 and 30ºC , compared to 'Kumagai' cultivar, depending on the wetness period and the species. The incubation period (between 6 and 7 days) and the latent period (between 8 and 10 days) were minimal at 30ºC. The data generated in this study will be useful either for the development of a disease warning system or for the increase in the shelf life of guavas in the postharvest.

‘Sweet grape’ tomato post harvest packaging

ABSTRACT This paper aims at evaluating the shelf life of mini tomatoes (Lycopersicum esculentum Mill.) cultivar ‘Sweet Grape’, grown in hydroponics, and stored under environmental and refrigerated conditions inside different packages. We adopted a completely randomized design, in which treatments were combinations of storage conditions: environment (e) and refrigerated (r) with packaging: polyvinyl chloride film (PVC); low-density polyethylene (LDPE); biofilm of tomato fruit of Solanum lycocarpum A.St.-Hil (lobeira) (TFB); cassava starch biofilm (CSB); carnauba wax (Copernicia prunifera) (CW), and without packaging - control (C). Physicochemical and sensory tests were carried out at the beginning (day zero), and at 8, 19, and 33 days of storage (DS). Fruit stored inside PVCr, LDPEe, LDPEr, and CWr had an acceptable shelf life of 33 days. The use of cassava and tomato starches were not effective in controlling fruit fresh weight loss. ‘Sweet Grape’ tomato postharvest conservation was enhanced under refrigerated conditions. The sensory evaluation results revealed that CWr treatment most pleased appraisers, while PCV had the highest rejection rate.

A conglutination test for rapid detection of antibodies against Babesia bigemina

A rapid conglutination test (RCT) with performance comparable to the indirect fluorescent antibody technique (IFAT) was developed to detect antibodies against Babesia bigemina (B. bigemina-RCT). The B. bigemina-RCT is a sensitive, specific, economical, and rapidly performed serological test suitable for field application or minimally equipped laboratories. This test had a sensitivity of 90.9%, and specificity of 97.6%, compared to IFAT, which showed for the same parameters respectively, 98.3% and 99.7%. The early detection of anti- B. bigemina immunoglobulins by RCT in experimental infections was nearly parallel to that of IFAT. Cross reactions were observed with sera from calves experimentally infected with Babesia bovis (1.8%) and with Anaplasma marginale (1.2%). RCT antigen prepared with non parasitized erythrocytes (negative antigen) showed 1.5%, 3.5% and 2.2% of positive reactions with sera from animals experimentally infected with B. bigemina, B. bovis and A. marginale. However, none of the sera from animals of endemic areas for babesia infection resulted in positive reactions with the negative antigen. Considering these results and shelf life over six months, the B. bigemina-RCT could be used for epidemiological surveys and evaluation of control measures against this species of Babesia.

Previsão de estabilidade de óleos vegetais através da rede de inteligência artificial

Redes Neurais Artificiais são técnicas computacionais que se utilizam de um modelo matemático capaz de adquirir conhecimentos pela experiência; esse comportamento inteligente da rede provém das interações entre unidades de processamento, denominadas de neurônios artificiais. O objetivo deste trabalho foi criar uma rede neural capaz de prever a estabilidade de óleos vegetais, a partir de dados de suas composições químicas, visando um modelo para a previsão da shelf-life de óleos vegetais, tendo como parâmetros apenas dados de suas composições químicas. Os primeiros passos do processo de desenvolvimento da rede consistiram na coleta de dados relativos ao problema e sua separação em um conjunto de treinamento e outro de testes. Estes conjuntos apresentaram como variáveis dados de composição química, que incluíram os valores totais em ácidos graxos, fenóis, tocoferóis e a composição individual em ácidos graxos. O passo seguinte foi a execução do treinamento, onde o padrão de entrada apresentado à rede como parâmetro de estabilidade foi o índice de peróxido, determinado experimentalmente por um período de 16 dias de armazenagem na ausência de luz, a 65ºC. Após o treinamento foi testada a capacidade de previsão adquirida pela rede, em função do parâmetro de estabilidade adotado, mas com um novo grupo de óleos. Seguindo o teste, foi determinada a correlação linear entre os valores de estabilidade previstos pela rede e aqueles determinados experimentalmente. Com os resultados obtidos, pode-se confirmar a viabilidade de previsão da estabilidade de óleos vegetais pela rede neural, a partir de dados de sua composição química, utilizando como parâmetro de estabilidade o índice de peróxido.

Determining economical TBHQ doses for corn oil stability

Corn oil obtained from a Brazilian industry, free from antioxidants and citric acid, added of different tertiary butylhydroquinone (TBHQ) concentrations, was submitted to accelerated oxidation in the Schaal oven test at 63°C for 120 hours and for 168 hours in a photooxidation chamber. Peroxide and absorptivity values at 232nm and 270nm were determined for this oil. From the Schaal oven test results, the best and the economical TBHQ doses were determined to this oil. Afterwards, a shelf life experiment was conducted and confirmed 115mg.kg-1 TBHQ as the best and economical dose for that oil.